1. The Field of the Invention
The present invention relates to procedures for preparing a root canal of a tooth for receiving a sealer and/or filler material. More particularly, the invention relates to methods for disinfecting a root canal prior to introduction of a sealer and/or filler material therein.
2. The Relevant Technology
When a root canal of a living tooth becomes infected or abscessed, discomfort and, in many cases, severe pain can result. In the early days of dentistry the only solution was to extract the tooth. More recently, however, dental practitioners have developed techniques to successfully remove the pulp material that forms the nerve of the tooth, which has become infected, and therefore save the teeth while preventing the spread of infection to the patient. After careful preparation of the canal that contained the infected nerve and other pulp material, the canal is refilled with an inert filling material, such as gutta percha, and/or a curable sealer or filler material. This process allows the patient to retain the tooth.
To achieve a successful root canal restoration, the dental practitioner must carefully, and as completely as possible, remove the infected pulp material. The pulp removal process typically includes shaping the root canal with one or more endodontic instruments so that it can be effectively and successfully filled and sealed with an inert material to reduce the possibility of further infection.
Cleaning and shaping the root canal in preparation for receiving a sealing and/or filling material is achieved by the use of metal endodontic instruments that include cutting surfaces for removing tissue in the root canal. Since root canals are seldom straight, often having bends and twists, at least some endodontic instruments are flexible so as to allow the instrument to follow the curvature of the root canal. Currently preferred materials of construction include stainless steel and super-elastic alloys, e.g., nickel-titanium (Ni—Ti) alloys.
In addition, even once the diseased pulp and nerve tissue have been removed, it is generally necessary to disinfect remaining surfaces and lateral canals of the root canal so as to kill existing bacteria, as well as to prevent later growth of bacteria and/or other microbes, which could lead to further degradation or even loss of the entire tooth. Typically, the practitioner chemically disinfects the root canal preparation, for example, by introducing aqueous sodium hypochlorite into the root canal, followed by rinsing the canal with pure water. Once disinfected and rinsed, the canal is dried prior to filling and sealing. Even with such chemical disinfection, there is still a risk that a significant bacterial population can remain and propagate over time (e.g., within lateral pores or canals that branch off the main root canal), thereby causing risk of further infect and pain to the patient. Improved disinfection techniques would be advantageous as they would reduce the frequency of or even eliminate sealed root canals later developing infection.